Ah I see, if it is making the case very hot and there is no way of keeping it cool then give something else a try. If nothing really suits the job then go single card. For me I got lucky, it had to be single slot or it would have cost $20 just to use it by replacing my wifi card. Single power connector as it would not have been worth it to replace my 85% rated psu.
Good luck There are a few single slot GTS 450s out now but the heat is still a drawback.