I recently tried VERY cruisery bars on my Kona as an experiment (they were old cromo bars going cheap) - 100mm rise with about a 45 degree backsweep - despite their cheapo nature they weren't superheavy for cromo (about 560g which is still a bunch lighter than many of the boutique cromo 'moto' style offerings around these days) but they felt like they weighed a ton
was an interesting experiment - TOTALLY changed the feel of the bike, but I decided it was too much of a good thing, so am going to go for something less extreme - I reckon around 60-70mm of rise with somewhere between 12 to 25 degrees of backsweep would be cool
I did a lot of research into options, including clamp size and so on and here's what I found:
quite a few cromo moto/mx bars around (both vintage and new 'boutique' options) - these will generally have 22.2mm clamps, have a lot of rise and in the case of the newer boutique ones be very, very wide. usually also tend to be very heavy. The cool new ones can get very pricey also. good examples are:
Surly sunrise bar (or sunset for even more rise and backsweep - both are heavy as f&*k)
Stooge tracker or junker bars (loads of rise and sweep, very wide, also very heavy)
Wilde Cardinal bars (ditto - also pricey)
Magic components Moth bar (60 degree sweep! also 900g!!!)
etc
there are quite a few old school 25.4mm riser bars available on auction sites from back when that was cool for DH in the early 2000s - these tend to be around 30-50mm rise, and quite a bit less wide than modern trends (eg 650-70mm) and won't have a huge bunch of backsweep. weight is usually more reasonable (circa 350-400g) - good examples:
azonic worldforce
DMR wingbar
raceface air alloy
easton monkeybars
cheap option but maybe a bit risky with old alloy bars that might well have seen some serious action
steel klunker/MX bars come up on ebay now and again, or even some suitable bmx bars (ie low rise for bmx) - usually cheap, but will be heavy
theres a couple of places where you can get modern 25.4mm equivalents though they will tend to be a bit wider -
NS bikes Proof (or Lick which is a 6061 cheaper alternative - both aimed at DJ and track - about 70mm rise)
Nitto B802AAF (nice bar, but maybe not quite enough rise)
Nitto X Crumbworks "KT Bar" (wide, a lot of sweep, only 40mm rise)
loads more new options at 31.8mm clamp - some of the ones I am still considering:
Nitto B801AA SB (similar to B802 above but 31.8mm bulged - looks like it has a bit more rise and slightly different shape)
Simworks/Nitto "cowcow" bars
Soma Dream Risers (lots of sweep available in both 50mm and 70mm rise)
Wilde/Nitto "Countrybar" (again loads of sweep, about 50mm rise)
Hunter/Nitto "smoothmove high riser" (really like this one but probably very difficult to get one in the UK)
some of the more modern MTB brands like Gusset/Deity etc do a higher rise version of their DH bars but it seems really high risers aren't the fashion these days for the most part
ergotec in germany have a few options as well - but maybe not the coolest choice