I have a similar sized bedroom in our cottage. 8' is plenty of width for a single bed. The bed is about 75" long. Add a few more inches for a headboard and consider it to be 6'6". That leaves 1'6" for walking space around the end.

I'd put two twins side by side with a nice sized dresser in between that doubles as a night stand for both beds. Wide enough to hold two small bedside lights and a clock. You may have room in a corner to angle a chair. Hooks on the wall are also a nice touch for visitors, to hang their clothes or a towel.

Get some blue painter's masking table and mark off on the floor the outline of the two beds with the dresser in the middle to give you a better feel of the actual walking room in that space.

Use a twin frame only and mount a headboard on the wall. If you are not into much DIY...You can buy a kit from http://headboardcraft.com/all_styles.php

and finish them yourself to add a nice put together look.

Here are a couple of layouts with your room measurements, to give you an idea of the space. The twin beds measure 36"x76" each.