Tell Me What I Need...

I`ve been all over the net and have been asking what I need to implement a passive sub (Revel Ultima) into my 2 ch setup.
What I have is very very modest by Audiogon standards but it works for me and sounds pretty ok IMHO.

I use a little Bellari VP129 phono pre that I run straight into a Parasound HCA 1500 amp (has RCA outs in back). My speakers are Revel F52`s.
The sub only has 1 set of speaker connectors (+ -)
So, I need a crossover and an amp and I want to relieve the main speakers of lower bass duty which I think is a nice idea given that they have smallish 6.5" drivers.

I`ve scribbled down a few suggestions as I`m not in any super hurry as I have a Rythmik 12 in use currently.

The factory optioned amp had 700 watts so I may need to be somewhat close or maybe not, as I only listen to music, no movies or video at all.

So what do you guys think ??
Am I missing something ? I see a 'views' count listed but I don`t see my thread !?`s fixed now.Never seen that happen before.

So can anybody steer me in the right direction. I want to start gathering pieces and I want to buy used.
But new isn`t out of the question.
An amp that`s been suggested is a Crown XTi 2000/2002.
One concern that I see with it is the high pass is fixed at 80hz and 6db slope. Would like a little more adjust-ability in that area.
See if you can find a NHT X2 or Paradigm X30. For quite a few more bucks, there's the Bryston 10B Sub. Rane has the 22S with summed output but that only has XLR.
Thanks..yes the sub only has speaker level connections so that has to be accommodated.
So I need to check those that you suggested.