I wouldn't consider using a wedge with an 8SE setup, it can be made to work but the mount isn't really appropriate for accurate tracking with a longer focal length scope like the C8 so it's a bit of a waste for imaging. If Kelly is really only interested in visual then keeping an SE in it's alt az orientation is the way to go. If imaging is really the desire then as mentioned a few times upgrading to a gem style mount is probably a better way to go.
The in between idea of using the Evolution mount is a good one if visual or simple imaging is all that's desired (short exposure work and EAA style observing/capturing with a nice fast camera setup).
The C8 on an SE mount/tripod is indeed at the limits but there is a nice upgrade that is already almost in place. Using the existing Ultima tripod under an 8SE mount is a really nice upgrade (all you need to do is get the appropriate length mounting bolts - they are 3/8" x 16 bolts but you have to watch the length of the threads with the SE mount as you can contact the gears inside if they are too long ... the solution is often just as simple as adding a few washers). It makes the whole package more stable and less vibration prone. This setup is also better without the wedge in place.
The Ultima C8 OTA can be de forked from the arms and a simple Vixen/CG-5 compatible dovetail bar added so the OTA can be easily mounted on an SE, Evolution or one of the smaller gem style mounts (they all the same type of saddle to hold the OTA). When purchasing a new dovetail bar it would be good to mention that the OTA is from an Ultima and to measure the distance between the front and rear mounting bolts. Those bolts are the ones with slightly raised heads (slightly domed) and there a number of them on the Ultima OTAs (they are usually used for mounting various accessories but are also appropriate for mounting the OTA). The bolts that are flat and flush with the surface of the front and rear cells are there to attach the cells to the tube in the middle and should not be touched.
The orange Celestron dovetail bar used on the SE and other mounts might fit the Ultima OTA without any modifications (the question is about the mounting bolts being in the right place for that OTA) but it might also be good to look at a product from someone like ADM Accessories who's solid bar is a bit more expensive but has more flexibility in how it's mounted.
So to recap ...
1) it's easy to remove the OTA from the forks and put a Vixen/CG-5 compatible dovetail on it. This will open up many different options.
2) the least expensive and primarily visual only setup is to use an 6/8SE mount, and with the Ultima tripod if you want a more stable setup than with the stock SE tripod.
3) an Evolution mount is a nice upgrade from the SE mount (smoother, more stable, carries a bit more weight) but more expensive (the Ultima tripod will work well under this setup too).
4) if more serious imaging is a desire then going directly to a gem like the AVX mount would likely be the most appropriate. But with the AVX you lose some of the easy of use of the SE/Evolution Alt Az mounts for visual work.