There aren't many tire options for our bike that come in a matching set. There are, however, many options if you don't mind mixing up tire brands and/or going to a slightly smaller tire up front.
The factory tires sizes are:
110/90-16 (F) & 130/90-15 (R)
The rim width for the front wheel is 2.5" and the rear wheel width is 3.0"
That being the case, a size 100/90-16 front tire will work on this bike. It does have an overall diameter decrease of 9mm over the 110/90-16 but that isn't really very drastic.
Samato has verified that alternate tire size 100/90-16 will mount up with no problem.
As well, the 120/80-16 alternate tire size is another choice for the front tire and has been successfully mounted by MRLMD1.
Factory replacement tires: 110/90-16 & 130/90-15
Dunlop D404 (only available through a Suzuki dealer)
Metzeler ME77 (only available through a Suzuki dealer)
Cheng Shin C906 & C907 (possibly no longer available)
Rear Factory Replacements: Kenda Challenger
Pirelli MT66 (Route 66)
Maxxis M6103
Cheng Shin Marquis
Metzeler Me 77
Factory Replacement Front:
GBC Green Shark
Metzler Lasertec
Pirelli Sport Demon
Avon Roadrider AM26
Conti Ultra TKV11
Kenda K671 & K673
100/90-16 Front: Bridgestone BT45
Maxxis M6002
Cheng Shin C6000
Kenda Cruiser
IRC Durotour
Matching tires with low profile front: 100/91-16 & 130/90-15
Kenda Cruiser
For more discussion and lots of info, see these posts:
viewtopic.php?f=10&t=722
&
viewtopic.php?f=10&t=1818
This list is not complete but will be updated as more options are discovered.