Hi Andy C, i got the same mods running on a 5770 and its doing 45-60fps, running like a dream.
I got a bit carried away with mods on Fallout 3 so i am keeping it simple this time and only got 7 running . My goals were a mod to improve things which Project Nevada does a fantstic job, I liked the EVE mod for the Laser weapons, a companion so i went for willow which is a realy good one, a hide out for my loot and stuff, a UI so it was darns ui which i think is the best, CASM for auto saves every 3 mins as i die a lot or game crashes , MNC for the Textures (Running the smallest one)
I tried Nevada Skys but agree with Pighardia, Project Reality and Imaginator realy make a big difference to the way the weather and MNCs textures look, its like having fellout installed , and dont forget to use the ATI or Nvidia graphics card fix, works a treat i got it running on Ultra Settings
I am finding with New Vegas that you need quite a few less mods to get it to the right level, which is hardly suprising since New Vegas basically is Fallout 3 with lots of improvements mostly added by mods in FO3.
With regards to how well it runs, i have a 965be ate 4.2ghz and a 69502gb with 8gb memory and i used NMC's medium pack. It looks excellent, but i am getting a hell of a lot of stuttering which could be lag due to the increased LOD or it could be due to NMC's i'm not sure yet. I will mess around with the ini to see what makes a difference
Another thing is that there are alredy loads of bugfixes etc for New vegas, and the New Vegas configurator is great also, which allows you to change some ini settings with the press of a button.
A few more very useful tools are Mod configuration menu and the Unified HUD project, which makes Project Nevada, DarnUI and Primary Needs HUD work together.
btw, the author of Project reality is releasing a new version at the the end of the month which will have lots of improvements, including more colour in the environment(i think it looks a little too grey atm).