I'll talk about my blue eggers later-
Slate legs are the worst when yellow legs are the goal because slate requires the dominant white skin plus lacking the Id gene(clears slate to white, clears green to yellow).
It is very unlikely to hit on single combed colored eggers if it is linked with the pea comb gene. They are located close to each other so they 'inherit' together all the time. They separate something like only once in 200+ birds, can't remember the exact numbers but the other problem is, it could happen in a cockerel and you would never know unless you majorly lucked out and kept him for breeding.... and then again lucked out by keeping the 'right' pullets... So yes, single comb is far far better for your project than any pea combed bird...
There is no linkage between slate legs and pea comb/O gene. It was just coincidence in your case.
The Legbar would introduce another potential problem- they are supposed to be e+(wild type red duckwing). It's recessive to wheaten so if you don't like it, it would be a somewhat difficult one to remove. The barring and crest are easy to get rid of- do a sex linked legbar cross and keep the non barred daughters and the barring is gone forever.. the crest is dominant but most of the time you can recognize the presence of it even on many day olds(the comb can have tells) so it can be relatively easy to get rid of but it does take a couple generations and a good number of birds- you already know it can get annoying how a perfectly colored bird happens to have the crest also... grr.. lol
If white ear lobes bother you... definitely go for legbars with less or no white in their lobes. It's a polygenic trait with both dominant and recessive genes and has the habit of surprising you by popping all of a sudden a couple generations down.
Edited by Kev - 3/2/16 at 10:45am