It would be intersecting to see how you will be without those mods. Universely electricity and computercraft will be two of your most used mods to come.
P.S I don't think forestry should be considered part of the " big tech mods" since it relies on buildcraft. My opinion
If I am correct, ulitamte is generally a bit more laggiest than direwolf. Other than that ultimate is the best. ( you can take out any mods you don't like) due the large amounts of mods, which mean in my opinion more things to do.