a well built wheel can last a long time, especially when built for the right purpose. building yourself wheels allows more options in terms of spoke count, mismatch hubs for weight, and crossings - especially because most lightweight clincher rims available to the public are laced to road hubs, and most track hubs are laced to pink vee's.

-velomine is good. forget this route if you want light weight, they sell dp18's and deep v's, all well over 550g/rim. even though the open pro/dura ace hubs are 350, you can do better for less (probably not in terms of hubs, but weight). velomine uses heavy straight gauge spokes, and thats not the lightest thing either.
-32h is no frills, especially when laced 3x. not particularly necissary unless you have heavy/ride aggressively/have bad roads. lower spoke counts does not really lower weight by a lot, its more aero but the disadvantages outweigh the advantages in most situations... 3x is the way to go, front and back, honestly. radial will not save you weight, might gain you some aero, but potholes will make you rushing to the lbs for a spoke tensioner.
-formula hubs are liked for their price, not weight or anything else besides sealed bearings obviously. i used to run dura ace lf hubs, i felt no difference, but if you like them and dont mind the price go for it, though they are no lightweights either as they too use solid axles.
-front road wheels are only used because of the skewer, rather than most fixed gear's solid axles. usually cheaper due to high availablility, but if you build your own wheels why not have a matching set, right?
-aluminum nipples are not weak as in they break, but they require frequent tensioning and are not worth the weight over brass nipples imo - also depends on the frequency of your rides/how you ride/where you ride

your wheels probably weigh around 22-2400 grams, judging by the depth/hubs. they should be strong though, im assuming theyre from a kilo tt pro/dawes sstal? i would consider getting wabi cycles prebuilt wheels, richard told me hes not going to have them at 150 for much longer - they are 1750g including the lockring, rim tape, and track bolts. thats pretty damn good, and at that price are a complete steal.

for under 400;
-kinlin 28h xr200 (390g)
-novatec road hub front (76g)
-dtswiss competition spokes, laced 3x

-kinlin 28h xr200
-novatec skewer rear hub (~250g, but no solid axle)
-dtswiss competition, 3x

should be around 1400 or so for the set, or 1550 for xr300s if you want a deeper profile. in fact that wheelbuild should cost you no more than 250, as kinlin rims are readily available on ebay for 40$/rim. stand + tm1 + spoke wrench may add up or you can use your fork/have lbs build it for you.

i forgot what else i should be answering. but ask away/tell me if i missed something. you can do the road front/track back, but good luck finding just a rear track wheel + a lightweight road front for a good price. build your own.