In respect of ultrasonic cleaners, you need to think long and hard about why you want one and what you intend doing with it, I have a 6LT jobbie and cost me around £200 a year or so back, I am now wishing I'd bought a more robust/well engineered cleaner. The one I have is a Chinese affarir, although that wasn't made clear to me at the time, so even if you purchase it from a UK seller, you need to check, I got caught out

The thing with the cleaners is its all about the frequency (Khz) and the number of transducers it has, for example, a cleaner with say 60Khz and 2 transducers will work better than a 120Khz cleaner with one transducer. The more tranducers a cleaner has the better, as it helps create the "cavitation" and distribute it much better throughout the bath and helps get into all of the parts.
As a guide, buying a cleaner with 4 tranducers with a cleaning power of 120Khz+ will be a good cleaner, of course the bigger the bath/cleaner the more likely it is to have multiple transducers.
The other thing to look out for is analogue versus electronic ones, the electronic ones are good, but the electronics don't tend to like the ultrasound very much so can be troublesome and break, also, ideally if you can afford it, buy one that will heat the cleaning solution to around 80 degrees C.
the last thing you need is a good cleaner, I buy mine from a place in Northern Ireland, I think I got 20Lt's delivered for £35 and you dilute it at 10:1 with water, so effectively makes up 200LT's of cleaning solution.
So to summarise all of that ;
1. Cleaning Frequency of 120Khz+ is best
2. Multiple tranducers (4 or more is great)
3. Analogue controls ideally
4. Will heat the solution to 80 degrees C and have a timer of 30mins
5. A decent size bath (4+Lts for carbs is great)
6. Never place items on the bottom of the bath, always have them suspended in a basket/cage etc
7. Use a proper ultrasonic carb cleaning solution
HTH
I'll take my anorak off now !
