I wouldn't call the 98 a light gun! It's only 500g less than the prosport, and you can order one in .25 to your door for about 400 quid odd

The 77K is the same weight as the prosport and is also shorter and can be had for less than the 98. It also has the bonus of a nice set of open sights.

Bear I mind if you order from Germany you'll have to respring the thing