[Shilly]

As far as bankroll concerns go, I'm not really going to lecture you. All that I'm going to say is that 4-tabling 2/4 with a $600 roll is a pretty bad idea.

Now for the computer. Getting a laptop or a desktop is a personal choice, and buying a nice laptop is going to set you back a lot more than buying a decent desktop. Let's look at the pros and cons:

Desktop:
Pros: More computing power, ability to use multiple, high-resolution monitors for multitabling, price
Cons: Not portable

Laptop:
Pros: Portable, ability to use as a second monitor if you decide to get a new desktop somewhere down the line.
Cons: Less computing power, resolution causes anywhere from a low to a high degree of overlap, price

If portability isn't important, just get a standard desktop. I'm guessing you could spend like $500-$600 for computer that will serve your purposes.