gsr..why? the b16 is pretty expensive for the performance u get..its small displacement = low tq.
the ls..well..its missing vtec so it has the lower end grunt..but no top end
the type r is just way to expensive for what u get..
so the best swap would be the gsr..
or if u want ..u can build and lsvtec..not hard but make sure u dont cut corners..this could cost u as much or more then a gsr swap depending on what u want.

this swap would be the best price/performance normally since u have more tq then a gsr with the same top end power..but its also a little harder to do correctly..

so for problem free reliablity a stock gsr would be a nice way to go..but if u want all motor..then build a lsvtec or b20vtec..using oem parts can net u some great hp..or go all out and build a nasty ass na motor.. its up to what u want to spend really and what kind of power u want..