Hi mldee
This one from Andrews Communication is 7" or 180mm with good price.
PROMAK180 OTA 180mm x 2700mm Maksutov-Cassegrain OTA has a 1.25" visual back and is gold in colour.
It is supplied with a matching gold coloured 9 x 50 finderscope in a white holder, 1.25" push-in diagonal, LET 9mm and 20mm eyepieces.
A Skywatcher aluminium carry case is not available for this model.
Now $1199.00 Complete package!
or if you want to mach black colour of your SW BD100 there is this one
BD-MAK180 180mm x 2700mm Maksutov-Cassegrain
OTA
You save A$100 or more off competitors' website prices as @ 26-02-09
$1999.00
Cheers