Digital BW, The Print

I've searched through various threads here, but haven't been able to 
find a full answer.  Being new to digital B&W, I've bene reading up 
on sprays and varnishes for inkjet prints.  Does anyone have 
recommendations for which varnishes/sprays are best for both (1) 
increasing Dmax and (2) archival permanence?

FYI, I'm using an Epson 2200.  Thus far, I tend to print on Enhanced 
Matte and Premium Luster for portfolio prints and on Velvet Fine Art 
for stuff I hope to sell.

Thanks!