Filters for monochrome astrophotography - need advice

[jusasi]

I'm about to step into the world of monochrome astrophotography (DSOs), I'm getting a mono camera, a filter wheel and now I need to decide what filter set to buy. I'd appreciate some wisdom from the veterans here.

What are the major differences in the filters and what details should I pay attention to?

I'm looking at these different sets right now:

Baader LRGBC + H-alpha filter set

http://www.teleskop-express.de/shop/product_info.php/info/p7812_Baader-2459521---CCD-Complete-Filter-Set-I--LRGBC---H-alpha-7-nm--1-25-.html

Seems nice, has probably all the filters I need for a while. Baader stuff is usually high quality. The description doesn't mention parfocality but at this price I would assume that's the case. Nice set but expensive.

ZWO LRGB filter set

http://www.astroshop.eu/zwo-1-25-lrgb-filter-set/p,44428

Cheap LRGB set, cheapest of them all. No idea about their quality.

Omegon LRGB CCD filter set

http://www.astroshop.eu/colour-filters/omegon-1-25-l-rgb-ccd-filter-set/p,33214#tab_bar_0_select

Another cheapish set. Not sure what to make of it.

Astronomik LRGB set

http://www.astroshop.eu/astronomik-1-25-l-rgb-filter-set/p,16756

Mid price, parfocality mentioned. Again I have no idea what to make of this.

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Out of these sets I'm keen on getting the Baader set, it's expensive but I trust the quality and I wouldn't need to buy the H-alpha filter separately. But to be honest I have no idea how big the differences in imaging are between these sets, I might be spending extra hundreds on nothing with the Baader set. However I'd rather not go all cheap and spend that 100€ to get something which I immediately might want to discard and get a better set.

In short, advice needed

[jusasi]

Forgot to mention, it's a CCD camera I'm planning to get, Atik 414EX Mono to be precise.

[johnrt]

Baader LRGB are the best in their price group. Don't buy cheap ones just to save money it will cost you more to replace them in the long run. The "Daddy" of the narrowband filter is the Astrodon, if you can take the slightly eye watering prices.

[Martin Meredith]

I bought the sets LRGBC + Ha + OIII + SII from Baader via Amazon for a decent price (cheaper than buying the two sets separately). They are indeed parfocal (and you can use the clear [C] filter for focusing). I use them for near real-time viewing and am very happy with the quality.

I also bought an Omegon 9-position manual filter wheel to house all of these. The 9th slot can be used to take darks (I taped a piece of flocking across). See my review here. 

Martin