I have no experience with either the Tamiya, or the Verlinden Steyr kits, but I will try to help a little.
First, here is a review: http://www.jbwholesalers.com.au/reviews/verlinden/v1409.htm
As far as detail sets from Verlinden go, I have purchased a few. Their PE is usually rather simple and would be great for a first time effort. So far, their resin castings have been decent, not many air bubbles to fill and such, but they are usually deformed a little, or do not have the best fit. Concerning the detail of the Verlinden kits, both their resin and PE is usually mediocre. And let’s not forget that the instructions are usually not very good at all. Their kits are usually not hard to put together, but try to stay away from complex resin offerings from them for a first time resin experience. Verlinden makes a wide variety of detail sets, and I find that they are usually a good place to start if you want to add a little extra detail.
In summary, the instructions will probably be terrible and you may need additional references. BUT, as long as you are not 100% anal retentive about your builds, like I can be, go for it.
good luck, and please keep us updated!!!