[G4] Internal Hard Drive compatibility for AGP

[JayB]

I've looked back through 6 mos of archive and read the specs at  
'lowendmac.com' but still don't feel l have confidence in knowing  
what I can buy to upgrade the internal drives in my G4/500 AGP  
(upgraded to an Sonnet ST 1ghtz).  It has factory 2x18 Ultra2 SCSI /  
Dual card drives.

My question is- can I buy pretty much any IDE drive to replace one or  
both the internals?  I know about the 128mb max.  But I just want to  
upgrade (cheaply) to larger drives without suffering speed (I thought  
the 7200 ultras were supposed to be the fastest).  Specific  
suggestions and sources would be much appreciated.

Also, are airport cards for older g4s like mine available?  (since I  
have a wireless router already in use for my laptop).

Thanks in advance,

~Jay