I recently purchased a mono setup from Theo (QHY) the QHY9 comes with a 5 position 2" filter wheel for 2500 overnight delivery. I have decided to change out the filterwheel to a 36mm 7 position starlight xpress filter wheel because it has a greater range of filters and runs from USB so only one chord.
I had a quick look at prices to make it OAG too
$2450 + $50 for QHY9
$473 for the 7 position SX filterwheel
$377 for a Baader 36mm unmounted filter set LRGB
$85 delivery for the last two items from teleskop express in germany
Total $ 3435
This gives you the option of ugrading easily to a OAG in the future if you like and also allows you to add the 3 Narrowband filters at a later date to your setup.
Another idea might be to invest in a OSC (one shot Color) CCD so you can build up experience first. I know I am glad I did (even if the CCD at the moment it is experiencing a mid life crisis).
