How big do chilli plants grow?

[Scarlet]

Mine has outgrown its allotted space- a four foot wide bay window. But I have had loads of fruit off it already.

[Apehanger]

Despite living up here in the Shetland Isles our south facing windows produce plenty of warmth in summer (the best day of the year in Shetland). Every window has 6 - 8 peppers growing.
This years Bell peppers have, so far, reached 24".
I planted Purple Tiger seeds last year and they produced fruit. This year they are about 12" and are heavy with fruit. I also have Habernero Red and Numex all in flower.
What I am really looking forward to is the fruit from my Bolivian Rainbow Chilli. I will be taking cuttings for next year and this years plant is going for THE CHOP!
This is what I am aiming for:

[Ovce domácí]

Tried 3 Ohnivec chilli plants, its a native chilli but got them from Real Seeds. Planted them late as well Apr/May instead of the recommended Feb but 2/3 have grown well. One is a good 2 ft, the other a bit smaller with about half a dozen chillies so far on the bigger one, smaller just starting to flower.

Planted a Jalapeno last year from some old seeds we had lying about in a draw for about 5 yrs, it grew but only produced a couple of mediocre peppers, this year its still alive in its pot after overwintering in the bedroom, half a dozen good looking peppers which we'll eat on Sunday as a salsa starter before a chillie without carne.