The 1.9 diesels (120 and 150 bhp) don't have DPF's in the Bravo. In the Bravo the DPFs started to be fitted when Fiat introduced the 1.6 (105 & 120) and 2.0 (165) Multijet.
Of these it was only the first year or so of 2.0's that caused problems, but I believe Fiat moved the position of the DPF closer to the manifold after a while, meaning it got hotter easier & therefore re-generated at lower speeds or at idle, rather than only when you were hammering it at high speed. This appears to have worked as later 2.0 Bravo's and other cars with the 2.0 diesel (such as the Alfa Giulietta) have very little (if any) DPF problems. The 1.6 doesn't seem problematic in any case, but like all diesels, it's not suited to long term urban use & needs a good drive once a week to be at its best.
The advantage of the 1.9 120 Multijet is that it has a solid 5 speed gearbox. The others get 6 speed ones, and the one in the 1.9 150 in particular (Vauxhalls infamous M32 box) is a bit of a dog with an appetite for bearings at anything over 40,000 miles.
Climate control is one of the other Bravo foibles (of which there aren't many to be fair). It's standard fit on the Dynamic trim but option on the lower Active and higher Sport trims. Unfortunately the 1.9 Multijet 120 with no DPF and good gearbox is only available on the basic Active or climate-control equipped Dynamic (you can't get a 1.9 120 Sport), so you'll need to decide between potential climate control issues, or gearbox/DPF problems. Or just get the basic Active spec and have none, but have a more basic car!
Personally if you like gadgets, go with a 1.9 120 Multijet Dynamic, which is a solid engine, with a solid gearbox, and just accept that you might have to fix the climate control at some point - though saying that its more likely that the 6 speed gearbox on the 150 diesel and the T-Jet will play up than it is for the climate control to break, I reckon.
Only Bravo to avoid would be the first batch of 2.0 165 Multijets, which are on 58 & 09 plate. After that they started to turn a corner & I don't think any Bravo's are as problematic as the (big arsed) Megane. Never heard of any water getting into Bravo's either.