List of UK resellers at:
https://wiki.shapeoko.com/index.php/Vendors#UK_2
If one is starting with just a 1/4" collet:
- three 2-flute 1/4" square endmills (such as the #201 endmills from Carbide 3D — one will be included with the machine, a pack of two will fill one out with: 1 for initial experimentation/roughing, 1 for finishing passes, and 1 spare. Downcut endmills such as the Carbide 3D #251 https://shop.carbide3d.com/collections/cutters/products/251-25-downcut-flat-cutter may be a good option for folks cutting wood.
- two 2-flute 1/4" ball end endmills (such as the #202 endmills from Carbide 3D) — if one wishes to do 3D modeling or cut parts which have rounded profiles along the bottom (often a good idea in woodworking for increased strength)
- two 90 degree V-bits such as the #301 from Carbide 3D — if one wishes to do V-carving or cut joints which use this angle
Add 1/8" endmills if doing fine/detailed work:
From: http://www.shapeoko.com/forum/viewtopic.php?f=35&t=6921&p=64848#p64848
- five 2-flute 1/8" straight endmills (such as the #102 endmills from Carbide 3D [11]
- two 2-flute 1/8" ball end endmills (such as the #101 .125" Ball Cutters from Carbide 3D)
- two smaller straight endmills (say 2 mm or so) (such as the #112 0.0625" endmills from Carbide 3D)
Additions:
- V-carving bits (say 30 and 60 degrees) — these are excellent if doing text
The following are special-purpose and only suited for specific usages.
- a stub 1 mm or 0.8 mm straight endmill
- possibly a small stub ball end too
My suggestion however would be to start by taking a survey of the endmills which are available (might be able to find a local reseller) and check which shaft sizes are prevalent, then source precision collets in those dimensions, then begin buying endmills.
(you should also buy a nice pair of wrenches, low profile 13mm and 22mm stubby)