Looking for buying K281.

Solution
By default there is only one SSD mounting location in the CoolerMaster K281 which is in front of the PSU mounting location internally.
94a0a22b4288a2bceb71bffbd1bdfc37_1361409207.jpg

You can get a better idea by downloading the product manual here and going through to Page 05.

https://youtu.be/WZg4KQhKfZE?t=43
^ in the middle of the cases bottom panel between HDD cage and PSU mount.

In essence you can convert your 5.25" and 3.5" drive bays with an adapter to accept SSD's but they would be technically cumbersome, expensive in some locations/regions or simply not accessible to most. If we knew your budget and purchase site(s)...
By default there is only one SSD mounting location in the CoolerMaster K281 which is in front of the PSU mounting location internally.
94a0a22b4288a2bceb71bffbd1bdfc37_1361409207.jpg

You can get a better idea by downloading the product manual here and going through to Page 05.

https://youtu.be/WZg4KQhKfZE?t=43
^ in the middle of the cases bottom panel between HDD cage and PSU mount.

In essence you can convert your 5.25" and 3.5" drive bays with an adapter to accept SSD's but they would be technically cumbersome, expensive in some locations/regions or simply not accessible to most. If we knew your budget and purchase site(s) we could suggest a better alternative to your aforementioned case. Perhaps the Coolermaster N200, provided you want to go for an matx board/layout?
 
Solution