Need a new headset for gaming and music. (€200-250)

as far as amplifiers are concerned, the stx should be fine for most choices.

you need to specify what you're looking for in terms of type of audio. do you want something detailed and competive (hear footsteps easy but very poor bass output), something fairly neutral (jack-of-all-trades, master of none), something v-shaped (detailed bright treble with good bass but reduced mids) or bass focused (weaker treble, fair mids, high bass). also are you needing open cans (big wide soundstage, depth to audio, leaks sound in and out, cooler to wear) or closed (small soundstage, less depth to audio, sound isolating, some can get a bit hot).

in europe, the dt770 (closed, v-shaped), dt880 (open, slight v-shape) or dt990 (open, v-shaped) are very reasonably priced. good bass levels, good bright high energy treble. comfortable. good headphones if you want something exciting.

while not as much of a price bargain since prices may be high in comparison, sennheiser hd5xx or hd6xx series are good more laid back and "mellow" headphones. good if you do not want harsh treble or bass and want all around decent neutral cans.

akg cans or audiotechnicas ad-xxx (open) and a-xxx cans are bass light so will be great for competitive gaming but not so great for immersion, movies, and music for most people unless you prefer bass-light cans. they do have some bass but not much quantity of it and not down to very low frequency.

if you want a clip on style mic, look into the modmic 4 unidirectional. otherwise, you might want to think about a desk mic, shock mount and boom arm if your needs are mroe professional than that.