Columbia trailhead 2 discs with RAW 80 cc engine?

I'm 5 foot 4 or 5 and the moondog is small for me. Couldn't imagine at your hight. The Point Beach is not gonna be that much better for ya. I am told the schwinn Jag is identical to the point beach. Maybe with a bent seat post to give you more leg room. Target has a good many bikes as well. Have you looked at Craig's list?

Have found some awesome bikes at garage sales, but think it might be to cold for them out your way yet this year.

I have never ridden or built a low ridder so I can't help much. (but am sure some one who can better advise you will jump in) If you get a chance to test ride a point beach, they are great for less then $200 bike. I just don't know if even with the bent seat post, you would be back far enough to be comfortable. Once your ridding a MB, it is very different then the ride you have on the same bike with out the engine. (makes shopping funny) For a MB, I like to be well behind the peddles unlike a bike where your more over them. Might just be me. The banana seat is really a great option (I just cought your joke)
I was admiring nogoodnic's ride, GT Kustom Kruiser Deuce Cruiser Bicycle. nogoodnic told me that it had an extra 4" in length. The thing I like about it is perfect fenders, good looks, double down forks and Apehanger handlebars. It is second on my list of bikes to buy. I have not been on one so I am just talking ascetics. Looks to be a one speed, coaster brake with no stock front brakes from that pic though. (Schwinn deluxe 7 is #1 and around $700)((..But Honey, I need another bike. the 8 we have now just don't cut it)
Drop him a PM or email if it looks like what you want. Really is a great looking foundation for a MB.

On the higher end, but below the Deluxe 7 are felt bicycles. Some great choices and local dealers will drop from the MSRP (Manufacturer's suggested retail price) a good bit. But they are still up there around $600's (check out the "MP" really cool) A lot of their bikes are just a tad to high for me, so might be a perfect fit for you. Thing about going with a good bike, is you then have a good bike. Although it is big cash.

...Could build a family Schwinn: 2009 Tango TandemMB

It's most likely been mentioned but why not get the jackshaft kit?
There is nothing like switching through your gears, listening to your engine rev up or down with each shift. It will allow you to keep your disc brakes too.
There is no "down side".

I have that bike 4yk4a. The engine fits like a glove and vibs are cut way down. The fenders are solid and it has those big 'ol tires. Really a great bike to motorize.

My pleasure, mean it. Glad you wrote, I couldn't remember the name of your thread. Wanted to tell you the down tube, where the front of the engine mounts is a little bit large for the motor mount. I had to make an adapter. If you don't have the tools to make one, there are about a million you can buy. They run from $5 up. Could force it on and I have done that but destroys the paint. Thatsdax has the best price that I have found. ENGINE_KIT_PARTS_PAGE_4

Gas Motorized Bicycle Motor Mount Fat Frame 'No Drill' Motor Mount | All Parts | Parts for Gas Powered Bicycle Motor Kits | LiveFastMotors.com Sick Bike Parts

There are a lot more. Also you can make one very easily.

I am looking forward to pics after you get her up and running.