i say spend the money, do it right and get your block sleeved regardless to how much boost your running. definitely do pistons. you dont wanna kick yourself in the ass later for something you should of done.

i have just heard to many horror stories of the H22 being boosted and melting pistons.
dont get me wrong though, there are those who have boosted H22s and they run fine.
like the guy above said get it TUNED correctly.
H22 + Boost = Heaven
i just dont know how reliable it is.
but if you do build the bottom end first i think you can have reliability and lots and lots of fun! check this place for your bottom end

Honda Prelude Vtec 1992-01 (No need to change Sleeves!)
Engine
Code Stock
Bore Includes: Kit #/Price
H22A1, H22A4 87mm Complete Gasket Set
Cometic Head Gasket
Mahle Gold Series Pistons
(87, 87.25mm bore) and
(8.9-1, 10.2-1, 11.3-1 comp ratio)
Performance Rings
Performance Wrist Pins
TOGA HP Main Bearings
TOGA HP Rod Bearings
Thrust Washers
Timing Belt
Expansion Plugs

Additional Parts Available (not included in HP Kit):
Turbo Kits
Connecting Rods (Eagle/SCAT/Oliver/Pauter) EKH28MPX ('93-96)
EKH28LMPX ('97+up)
$929

Call to Order:
(603) 378-0090

Pro Comp Engine Kit Also Available:
Includes parts listed above with:
1. Re-Con Forged Crank
2. H-Beam Rods
Kit #
EKH28MPX-PC (93-96)
EKH28LMPX-PC (97 & UP)
Price: $1529