It's pretty easy to lower the tank shelf on this kit; just cut the locator tabs off and put it where you want, you may need to trim it for width. About 1/2" or so lower is about right. You should also measure your prop hub to firewall distance , make sure the 4-stroke and whatever mount you're using will fit okay. I moved the firewall back about an inch on mine to fit a .65 Saito. There's just enough overlap in the cowl for this.

As for sideways or inverted, like already said, depends on how scale do you want. Mine's inverted; I installed an on-board glow, but I really don't need it, the engine is dialed in and runs fine without it. I use it to start up, because the glow plug IS difficult to get at.