For your tank and volume, I'd recommend a Geo 612 or 618 in that brand lineup. Main difference between them is the volume o media they hold. I think they'd do fine for your system requirements. You would just fill up the 612 a bit more often with replacement media.
I'll let someone with more MRC reactor experience recommend the appropriate MRC Model. I use GEOs exclusively on my system, but you would not go wrong with either brand, IMO.
I did a price comarison between the MRC and GEO units, and their pricing is about the same. The MRCs start lower, but I think there are options on MRC that are standard on GEO, like a ph probe holder is optional on the MRC vs standard on the GEO. GEOs use Eheim recirc pumps in their reactors, vs Mags or Pan World in the MRC. Once you have them comparably equipped, I think the pricing is pretty close.