Just received 2x ibm ultrastar 20 gig 7200 rpm scsi. (gift

)
I have 2x 40 gig maxtor 7200 IDE hard drive...
but I'm planning to buy ss51 g / 2.4 ghz... and WANT to use my 2 ultrastar scsi... will make them software raid 0 with win xp after...
I really wanna use them and the only thing is missing is the scsi card...
I'm ready to sacrifice 40 gig of hard disk space for performance, noise ( yeah! the ultrastar are quieter...

and compatibility... (I use linux...) not sure wich scsi card works great with linux....
in fact , scsi hd runs hotter.....
But!
What do you say?
will it be too hot? ( can i add a fan in the back of the hd's? )
drawn too much power? (i think its the same...)
does the performance of 2 scsi hd in soft raid will be faster than 2 ide?
What will you do if you where at my place? keep the ultrastar and sell the 2 other hd? or keep the maxtors one and return the ultrastar?
I need as many opinions you can give me because I REALLY wanna buy the ss51g and still have a performance computer....
I have the ANTEC file server case, (wich can hold all my hdd's but will sell him: too big and too loud...)
Sorry for my english..

MANY MANY THANKS!!!!!