Charlie, since Festool offers a 10% off tools with the purchase of an MFT I do recommend you pickup something, anything to get that deal. Great if you need a sander, router, dust collector, etc, but a Sysrock radio counts as it has a serial number, as do the led lights. You can always resell them and still come out ahead.
The 2700mm rail suits me fine, and I can always connect more rails onto it when needed, like when building long counter tops out of Corian.
I too agree on just buying the complete kit. You can cut the rail down if you want a shorter one, or just sell it. I have multiple fences to choose from, but often use the one that comes with the MFT/3. I use the end clamp near the rail and then just use a grip type clamp on the end to set 90* and keep the fence in place. Probably should buy another end clamp for $39 at some point.
The accessories that go along with the table are going to be an added expense. Dogs are great to have, and 4 is a good number (I bought Precision Dogs, but there are many brands including Parf dogs which Peter Parfit from here helped design). Clamps are a necessity. The Dewalt clamps work great for some things but don't fit into the MFT holes without modification, so at least a couple of the Festool Quick Clamps are nice to have. The Clamping Elements are a must have too. I have two sets for a total of 4 clamps.
From there you can make a few accessories. Rip a ^ out of hardwood and it will fit into the MFT grooves upside down to support tool holding boxes (Screened bottom lets the sawdust fall thru), saw holder shelf, wood chip deflectors and anything else you dream up.
