12mm Nagler t4 vs. 14mm Meade UWA

I'm in the process of upgrading some of my equipment (in time for the Transit of Venus - which I have a premonition that it will be clouded out for me!)

My main instrument is a 8'' f/5 dob, and I have a couple of achromatic short tube toys that I take on tramps. Current line-up is as follows:

40mm UO MK-70mm (main low power)
24mm TAL UWA (just won't reach focus on my dob, will on refractor, is there a low profile 2'' adapter available somewhere?)
5-8mm Speers-Waler zoom

In addition I have a 19mm Axiom and some Skywatcher super wides.

I've decided to sell my 40mm Konig in favour of a t5 nag 31 (ouch, but I did get a pay rise last week and it's my birthday next week), and am thinking of getting something in the 11-14 range. I also am either getting a 1.6x or a 2x barlow, would need your opinion on the best choice re: power ranges.

Note: I am a spectacle wearer so er is an issue. Also I am more a dso person than planetary.

That is a tough choice. I have both the 12mm T-4 and the 14mm UWA and I can not state which is superior. The 14mm is extremely flat fielded and very sharp with good throughput and shows nebulousity well. The 12mm Nagler also shares these traits and works well with a Barlow. The 12mm might be slighly lighter than the 14mm UWA. I would hate to have to choose between the two, but I use the 14mm UWA more than the 12mm Nagler I would say.
The 31mm Nalger is in a class all alone. I also have on of those. :^)
Floyd