You'll know well enough to play around with sizes according to water height and colour Rob, I'd look at tubes from 1" to 2" in aluminium and copper. If you really want to get down a bit tubes in tungsten and brass can help but so will coneheads and to be honest the coneheads can 'swim' better than very heavy tubes on their own.
Pattern of fly is always a little subjective in the spring (arguably most of the season through) and confidence in the pattern and how it's presented is probably more important.
However, a selection including the following would be in my box: gold bodied willie gunn, silver willie gunn, posh tosh, eternal optimist and probably a cascade. Patterns heavier in silver, gold and with yellow in work for me at this time of year. I like a green and yellow combo (eternal optimist) but they're not everyones' cup of tea. When those frustrating days come along, pays to have a monkey and a sunray shadow or two to play with too
Get tying
H