Shinkos are probably the best bang for your buck with these bikes.  I ran a pair for a while and they worked fine.  They might wear a bit faster than some brands, but the cheaper cost balances it out.  I swapped my front for one with a tread pattern similar to what yours has, but a modern equivalent.  I'm not a fan.  She looks better, but doesn't ride as nice.
Plenty of selection for the front, but the rear is a bit of a goofy size.  You still get options, just not as many.