StillSmart

I'm interested in the custom element? Whats the thread, whats the watt density per inch etc.

I ran a std copper hot water element in my keg with the 2-1/4 BSP thread - got one in my new keg too.
They are cheap as chips (about £12 from BES) so if its got a short life then it's easily replaced - haven't burned one out yet though.

Hehe, I knew it wouldn't be cheap. I have used the long elements and bent them to fit with a bit of heat.
Both were second hand and it wouldn't be the end of the world if I ruined them. I checked the resistance before and after - no change - I've had no problem.
The longer length will equal a lower watt density - might struggle if distilling on the grain - if a open top still stirring on the warm up will help - I let it get up to 50oC before putting the top on if its something I think may burn.

I'm positive no-one will advise you to bend an element, ruining it or at least shortening the life is a very real risk - just letting you know I did. I got both of mine when buying copper boilers for a pot still - first one had problems, the second is a work in process - so were a by product and didn't "really" cost me anything - I would think twice about something I paid cash for.

you can always use one the correct length ideally one that doubles back on its self - effectively what I did, but done by the manufacturer.

I fitted 2-1/4" BSP Essex flange to my fist keg - this was slow & very very noisy when cutting, and it ended up leaking a little, and I had to buy some food grade sealant to sort it.
I went with the stainless 2-1/4" full socket for my new keg.

If you have committed to the 1.5" socket, I guess standard elements wont be an option for you. These guys do alternative threads - no idea on cost.
http://www.tpfay.co.uk/OurProducts/immersion_heaters.aspx