I've planned out the pedal board I intend to build today (have most of the pedals with a few in the mail, and I've just ordered the board/psu I plan to use).

Anyway, I've managed to find a way to get it to all fit within the space I wish to use, it just requires me to patch from certain pedals to other pedals that aren't directly next to them. As such, I need a few patch cables that are longer than your usual 2-3" ones, but shorter than a full on instrument cable.

I'm going to need a few of varying lengths, with the longest being around 40cm / 15". I've looked around on the internet but I can't find anywhere that sells cables that aren't either too short or excessively long. Anyone have any suggestions for places to look to get a variety of different sized jack-to-jack cables?

EDIT: Would help a lot if they're available in the UK, too.
Spare a Cow
Eat a Vegan
You won't be able to get 15" ones, unless you make them yourself. They usually come in 1' or 3' lengths. If you want to make them yourself, lava cables, george l, planet waves, and Core-X make solderless cables, and if you want to solder, you can get the parts from most music stores.
Peavey Classic 30
PRS SE Custom Semi-Hollow
+some pedals
You're best bet imo would be to go on UK ebay and look up "bullet cable" and look for the kits. Super high quality and crazy easy diy cables! Look up a video or two to see how simple it is.
Jackson DKMGT
Squier CVC
Peavey 6505+/Mesa 4x12
TC Polytune
ISP Decimator G String
Green Rhino
MXR Phase 90
MXR 10 band EQ
BBE Sonic Stomp
Guyatone MDm5 Delay
Guyatone MD3 Delay
TC Hall of Fame Reverb
Thanks for the suggestions. I started to think that. I'll probably just bust out the soldering iron if I need to. Funnily enough, I just found a few ~50cm cables in my box of miscellaneous shit anyway that ought to do the trick. Cheers.
Spare a Cow
Eat a Vegan
If you're OK with soldering, you can make cables pretty easily. Someone else will post a link to a website that sells bulk cable and ends, I forget the name of the site.
Telecasters-->Dunlop Volume Pedal-T1M Pearl-AMT Japanese Girl Wah-Line 6 M9-Ibanez DE7-EHX Cathedral-->Mesa Boogie Nomad 4x10 combo
Go George L cables.
I have a full switching system that requires alot of varying size cables and one of those kits does it all.
And I'll you do is cut the cable to length, insert it into the jack and tighten 1 screw and you're done and its all reusable so if you move stuff and get new pedals its simple to make new ones again.
I make my own so they are exactly the length I need. Have a roll of cable and a handful of plugs tucked away and 5 mins later you have a custom length cable.
Gilchrist custom
Yamaha SBG500
Randall RM100 & RM20
Marshall JTM45 clone
Marshall JCM900 4102 (modded)
Marshall 18W clone
Fender 5F1 Champ clone
Atomic Amplifire
Marshall 1960A
Boss GT-100

Cathbard Amplification
My band
Mogami bulk cable and Neutrik plugs...

Mesa Royal Atlantic
Laney LC15R
Emperor 4x12 Silver Bells
Gibson SG Standard
LTD Viper-500
Catalinbread Ottava Magus
Jim Dunlop CFH
MXR Carbon Copy
EHX Epitome
EHX Superego
Fuzz Hugger Algal Bloom
Way Huge Fat Sandwich