check universalmania.com I ordered my hds from them and have always heard they have good customer service. I believe the price was about the cheapest I found at the time too.
I’m not sure if you can hook up an external GPS to an internal or not, but i do now know that you can ethernet hook an internal GPS unit to another unit that has the External GPS and your internal GPS unit can share the external GPS puck.
Otherwise, the internal GPS is junk compared to the puck.
I got my 999 from ExtremeNavigation for $1,200, then got the $200 rebate….now it looks like all the online retailers raised their prices due to the high amount of purchases…
In exactly your shoes with a 597ci hd di. Now I have a 999ci hd si courtesy of universalmania.com. Still in the box and looking forward to getting it mounted and testing it out.
The combination of larger screen, si, and rebates pushed me over the edge.