Hi ptc,
I buy heaps (ok, most) of my gear online... but for things I need to get fitted (like wetsuits, gloves, booties, masks) I'll buy them where I try them on... even if it is more expensive. I baulk at paying $595 for regulators I can buy online for $319, but if you've been to an LDS and tried things on there for fit, it's only fair that you spend your money there. Most LDSs are independantly owned, not chain stores, and if you're taking up a staff member's time with trying things on so you can walk out the door and buy it online cheaper, the owner still has to pay wages even though there was no sale, and instead of giving the shop cashflow, you've incurred a financial cost to them! It's just not cricket!

But anything I can research myself though on the web that doesn't need fitting, or isn't available locally, I'll buy online.
I've had nothing but excellent service from LeisurePro, and can't offer any recommendations on the masks you mention, other than buy the one that fits you best, and all other things being equal, if one has a lower internal volume than the other, get that one, as it will be less of a hassle to manage mask squeeze and equalising. Also look at the straps and ease of adjustment while wearing gloves if you're doing cold water diving.
Ben