i thought i'd offer a tutorial on how to make krooza "blanks" which you can then modify
you'll need an old school HK missile box, one half of a tank barricade from the scenery sprue, one half of a las cannon, a bit of old school ram, and two small pieces of the chaos vehicle sprue - the decorative squares. Finally you need a bit of flat plastic for the tail piece - i use bitz from some speeders i cut up.
put the missile box together, sand the box smooth.
cut the tank sprue as shown - sand the cuts smooth - leave the front piece as is but you can cut the rear piece at any angle you want.
attach box to tank sprue bitz - leave some space in front so you can add the square plastic bitz at the same angle as the tank sprue
put first square on rear end of assembly - straight up and down -- it will form the base of the "T" for the tail fin
second square piece goes on an angle in the front - don't worry if there is a little space there
pin drill hole in bottom -- add base
cut lascannon just behind the muzzle guard as shown (you can use the holey piece as long as you eventually cover the hole with something or make it part of your design)
Glue it to your blank - i like to line up the straight edge and let the jagged edge hang over the side a bit
add your tail fin
now you are ready to add gubbins, guns, prows, etc. - the whole process of building the blank should only take about 10 minutes.
oops forgot the last step - cut off two teeth from the tank ram and glue like a jaw to the front - sorry no pics.