I have both a PS3 and 360, and although the PS3 is the better console of the two (imo of course), I can give some answers to your questions:
What do people think about Elite or Arcade pack's?
I have a Premium from last year, but of the two you mention, the Elite is the only one with HDMI, as far as I know, it also comes with a 120gig hard drive.
What about waitin' for Blu-ray drives on the 360?
Is this confirmed, or just a rumour? If you want BR and gaming in one unit, the only option at the moment is a PS3, but you don’t get a massive choice of games – although it’s not too bad now imo.
Are they really that noisy (360's) generally?
Yes, as you are a PC Gamer, picture several Delta fans at full pelt, and that’s when it’s idle. Heck, it’s probably louder than the old GeForce FX

At least mine, and the majority of owners find this, it’s even worse when the CD is spun.
The hardware design fails

Seriously though, I think it was a little rushed to market so the older ones (new ones too?) are likely to eventually suffer from a RROD. Whether this is linked to fans or not, I have no idea, but the general consensus seems to be 'it's a cooling problem'.
What about the separate HD drive?
BR ‘won’ the new format wars, so I expect these can be had cheap, same goes for the films, but I very much doubt that you will see any more films released on this format. For me personally, I don’t see much benefit over DVD.
Whats a good price to pay for these consoles?
I’m guessing somewhere in the region of £200-£300+.
Being a PC gamer at heart, can i get a keyboard/mouse combo for a 360?
Not as far as I know, you can plug a USB keyboard in, but cannot use it for gaming, there was some third party bit of kit coming that allowed the use of mouse and k/b in-game though.
Scort.