That is not a bad price at all for the work done...you are smart for getting the head freshened up IMO 
A couple of things...in no particular order:
- The RA spec for HKS MHG's is 30 RA minimum...as mentioned, the lower the better.
- Find out from the machinist how much material was removed from the head...if significant, you may have to replace the MHG to keep cylinder compression ratio correct.
- You can re-use your HKS MHG if it has no damage (at all) and all the old viton coating is removed...acetone or paint thinner seems to work best for this. You will need to use copper spray once the viton is removed to effect the initial seal.
- Use ARP studs or bolts to secure the head. Follow the torque pattern in the TRSM...I use 10 ft/lb increments. Use the torque spec on the sheet that comes with the ARP hardware...the spec is different for moly vs motor oil for lube. ARP recommends 5 loosening/tightening cycles before the final torque...this is especially important if you use motor oil for lube:
http://www.arp-bolts.com/Tech/TechInstall.html
- Consider having the exhaust studs helicoiled while the head is off the car...easy to do. These studs have a nasty habit of stripping
- Check your valve shim clearances (as you mentioned) before you install the head...again, easy to do with it out of the car. Also check your cam shaft clearances, proper cam cap installation order, and cam cap torque. The cam caps have a torque sequence in the TRSM.
- Use new cam shaft seals and valve cover gaskets.
- Make sure you apply RTV in the two locations on top of the timing cover where it meets the block deck per the TRSM. This is done before the MHG is laid down on the deck. You don't want an oil leak.
- Take a close look at the big banjo bolt fitting at the rear of the head...if it is rusted, replace it. Replace the two small 90 deg hoses...one attaches to the mentioned banjo fitting, the other is behind the water pump.
- If you lap the block deck in the car, diamond paste is the fastest. Make sure you block off the oil/coolant passages...foam ear plug work well...get a needle and string to thread the plugs through the middle so you can remove easily when finished lapping.
- Clean the cylinders with Mopar combustion chamber cleaner...after you lap the block. Make very sure the block deck is squeaky clean.
A couple of things...in no particular order:
- The RA spec for HKS MHG's is 30 RA minimum...as mentioned, the lower the better.
- Find out from the machinist how much material was removed from the head...if significant, you may have to replace the MHG to keep cylinder compression ratio correct.
- You can re-use your HKS MHG if it has no damage (at all) and all the old viton coating is removed...acetone or paint thinner seems to work best for this. You will need to use copper spray once the viton is removed to effect the initial seal.
- Use ARP studs or bolts to secure the head. Follow the torque pattern in the TRSM...I use 10 ft/lb increments. Use the torque spec on the sheet that comes with the ARP hardware...the spec is different for moly vs motor oil for lube. ARP recommends 5 loosening/tightening cycles before the final torque...this is especially important if you use motor oil for lube:
http://www.arp-bolts.com/Tech/TechInstall.html
- Consider having the exhaust studs helicoiled while the head is off the car...easy to do. These studs have a nasty habit of stripping
- Check your valve shim clearances (as you mentioned) before you install the head...again, easy to do with it out of the car. Also check your cam shaft clearances, proper cam cap installation order, and cam cap torque. The cam caps have a torque sequence in the TRSM.
- Use new cam shaft seals and valve cover gaskets.
- Make sure you apply RTV in the two locations on top of the timing cover where it meets the block deck per the TRSM. This is done before the MHG is laid down on the deck. You don't want an oil leak.
- Take a close look at the big banjo bolt fitting at the rear of the head...if it is rusted, replace it. Replace the two small 90 deg hoses...one attaches to the mentioned banjo fitting, the other is behind the water pump.
- If you lap the block deck in the car, diamond paste is the fastest. Make sure you block off the oil/coolant passages...foam ear plug work well...get a needle and string to thread the plugs through the middle so you can remove easily when finished lapping.
- Clean the cylinders with Mopar combustion chamber cleaner...after you lap the block. Make very sure the block deck is squeaky clean.