I've got it working well with 188.8.131.52. I've also modded EFLC successfully with no problems and it looks great.
I've done some more modding since the above shots and it looks really good and plays smoothly. These shots are from Lost and Damned again and you can see the difference from the above shots.
You do need a mod to fix the taxi bug. I use the 'real traffic taxi texture fix'. Another common problem is the 'red sky' glitch that can be caused by modding sky textures. There's a fix for it, just google 'gta 4 red sky' if you need it.
Also you should be careful with your card. You've only got 1gb of Vram, so be aware that overreaching your card's abilities causes nasty pop in and lag. The settings may say you've got enough room but it doesn't factor in modding, so you may need to turn things down a bit to keep it running smooth even if the resource tally says you've got spare vram.
Don't forget to set up your commandline.txt file in your GTA IV Root folder and make sure these lines are present. It helps a lot with keeping texture pop in and other issues at bay.
-nomemrestrict [delete the -memrestrict line after adding this if there is one.]
-availablevidmem 2.4 [you'd need to put 1.0 since your card only has 1gb of vram, don't go above 2.4 no matter how much vram your card has.]
If you need 184.108.40.206 for a particular mod it will say so. I wouldn't worry about rolling back unless you have a specific mod that you really want to use that requires it. Most of the more recent mods are made for the latest patch and most, but not all, will run in either GTA IV or EFLC. I've got it running great on the latest patch with no issues.
Also, make sure you pick up Spark, OpenIV, and either xliveless or IV Asi Loader [you don't need both]. You need these tools to mod.
I know you don't need it, but others should be aware that GTA IV does not like multi-GPU setups and performs better without SLI or Crossfire. If you've got it, turn it off and the game runs much better.
The game looks great modded, and there's tons of cool stuff you can do with it.
Also, be sure to pick up the Simple Trainer for GTA IV. It's got some really cool features. It's more than a cheat tool and you'll need it for some mods. Most trainers are just for cheating, and you can do that with this one, but a lot of mods use it to adjust their settings so you really do want to have it if you're modding the game. Plus, there's a Gravity Gun programmed into it, and that is all kinds of fun in GTA.