Hey Afan, I too am planning a trip for the end of April. A bit longer than yours, from Lancaster PA to Denver CO and back, about 3400 miles and 48 hours of driving. I actually may be going right through Des Moines. I will be taking my stripped down 78 goldwing this time, but I have done lots 2 and 3 day trips on my savage.

Anyway, I considered bringing a patch kit, but after changing my own tires recently, I would not want to have to do that along the side of the road, possibly at night, possibly in the middle of nowhere. Plus all the extras I would need to carry like tire spoons, rim protectors, mallet, tire lube, extra tube or patch kit, air pump (it has to be strong enough to reseat the bead!)... A can of fit a flat is more compact and should be enough to limp into a town that can fix it right. That way, at least I could relax with a cup of coffee while someone else does it instead of fighting with tire along the side of a highway for hours.  

I have never gotten a flat on a bike, and with almost new tires, it is even more unlikely. Tire changing can be a major pain and can take a long time. I would rather enjoy my vacation.

You can also do your best to avoid the things that cause flats.  If you stay on the paved road......your chances of getting a flat are slim...but it does happen on occasion.  I did hit something on an exit ramp at night that put a whole in the sidewall of my car tire - but other than that the flats have always been caused by "OFF ROAD" stuff.   Also there is a metal recycle place down the street from my office, and there are often some loose car parts in the street that have fallen off the crushed cars that are being hauled on the flat bed trucks.

If the rain comes down hard and you head for an awning at some vacant and fire damaged building......watch out for broken glass.  I got into that situation at the last Dragon Run and had a couple of small pieces of glass in my front tire.   Also avoid pulling over on the shoulders, where I got  a hunk of fence wire stuck in my tractor tire.  Almost any flat I have gotten has been from driving in construction sites, the edge of the road, abandoned buildings, etc.

And if you haven't changed 5 or 6 tires in the comfort of your garage.....the side of the road is not the place to do your first one.  The process of getting the tire off the rim, and learning how to put the tube in without getting it pinched and putting new hole in it does take a bit of learning as well.

If you are not a AAA member or your insurance company doesn't have it, then joining the American Motorcyclist Association will get you free road side assistance.....if you sign up for their automatic renewal option.