#1
So my dream guitar may finally become reality, but I've got one thing potentially holding me back: my bridge.

I want a 7 string, with the 3 highest strings doubled up like on a 12 string.
I was going to buy this bridge:

http://cgi.ebay.com/7-STRING-CHROME-Tune-O-Matic-Guitar-Bridge-L7-/110425032128?cmd=ViewItem&pt=Guitar_Accessories&hash=item19b5d845c0

And then take 3 saddles from this bridge:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=200459111014&rvr_id=116860628274&crlp=1_263602_263622&UA=WXF%3F&GUID=1a82de4612a0a0e20527ba57ffe14bf0&itemid=200459111014&ff4=263602_263622

and put them on the 7. But I noticed the height measurements are slightly different.
It SEEMS negligible to a complete amateur like me, but that .2mm in height might matter?

Thank you guys.
Agile Intrepid Pro 828 Natural w/ Maple fretboard
Agile Hornet 7 w/ custom steel pickguard
Mesa Boogie Single Rectifier w/ 2x12 G12T-75 cab
Maxon OD808
Boss HM-2
#2
From the drawings it looks like the actual bridge pieces are obviously different dimensions to account for the 7th string, but the saddles seem to be the same size.

Should be fine, though if it isn't it's only a $20 loss with a resellable bridge.
Skeet UK is awesome, he can get WD Music parts discounted.
#3
Well I think an issue you will run into will be the bridges are 2 different styles. One uses the retainer wire the other uses the little nuts. The screws aren't interchangeable between the 2. Looking at the drawings its probably not likely the saddles will be interchangeable either.

You might look for a TOM bridge where the saddles are blank with no slots and just do the string slots the way you want.