so what motor do you have now?
EDIT: did a search and found the DB2 is a GSR integra, correct?
so assuming that info is correct i am gonna vote for LS block with your vtec head... cheapest option by far... you may want to get head work done, a rebuild AT LEAST esp with thosehigh miles, and possible port and polish if you find a reasonable price for the work...
you could always run a compression test prior to ripping the motor down, just to see how the head holds compression, perhaps you can get away with no head work? even cheaper...
EDIT 2: ls-vtec option still choice number one, but since you will have it torn apart you should build it for FI while you have it ripped down...
look into the cheapest way which i think would be a combo of diffrent internals to lower compression for more boost... and of course head work to prevent valve float...