I need a Apexi Head gasket bore size 86.5mm and thickness 1.8mm or 2.1mm will do. Does any one have one not been used?

You will probably have to go to the likes of twosrus in the states to get items like that, or maybe MWR.  Also, might wanna get the head checked for integrity, if you've been constantly cooking it.
 
Alternatively, get a stock ST205 gasket, drop the boost to a reasonable level and retune on that.  Will eliminate issues down the track.

Ah.... that's gotta hurt!
 
http://www.ebay.com.au/itm/Apexi-Metal-Head-Gasket-MR2-SW20-Celica-ST205-Turbo-3S-GTE-B-88mm-T-1-1mm-/261495891202?pt=Motors_Car_Truck_Parts_Accessories&hash=item3ce25ea502

Yup... bout that price O.o  ST205 lookin' much better now!
 
Just seen the pics of the head... it got hot.  REAL hot.

I have a std gen3 mls hg Available.

I ended up having to get mine via Ebay.

Will get the head welded and refaced and check for problems, should cost $150.00 to fix the head. It's the head gasket that costing. Ideal is to get a 1.8mm thick Gasket Save lots money on a retune. Still be lowering boost a little.

Just drop the boost and run a thinner gasket.
 
You can make the car more driveable that way by bringing the static CR up to a streetable level and it'll make hillclimbs much more fun!

we have various metal HG's in stock. i hope you know the Gen 2 and Gen3 ones are different. 

I have a brand new unopened apexi gasket here (obviously gen 3 as that is all apexi make).  1.1mm though.
 
Cheers,
 
James.