Something capable of big lows? what kind of cab do you have? thats going to be your best bet on getting the tone you want. otherwise its down to EQ and technique.
How loud do you want it to be is another question you need to ask. Your budget is going to put you into used tube amps, which he has used, or you could go the class D route and get something new. Looks like its about $1/watt from the little research ive done on the class D amps as im a tube snob.
Problem with Eric is that he seems to play a few different rigs over the years, and different basses. Most of his rigs used big cabs regardless of brand or what powered the cab.
I use a B15 through a 2x15 cab, roll the tone back on the pbass just a tad, and play somewhere between the pickup and neck to get the feel for his style....
good luck!