i think that this depends of 3 things:
where comes most of your traffic from
what size will be most of your files
how many links will be in every post
and how many files will you upload everyday

for example for tier 4 or latinoamerica there are not many options u can try these:

Uploadstore files between 100-400MB
Profitupload files between 5-300MB
PyramidFiles files bigger than 150 MB
Freakshare files bigger than 450MB
Depositfiles latinoamerica all files
Uploading.com files bigger than 50 MB
Bitshare files bigger than 100MB
Usershare files bigger than 100MB

but every filehost has his own rules so you ave to make decisions
this is just an example to tier 4 or latam
but in tier 2 or tier 1 there are better options than these

sorry for my bad english

duckload is not good idea if you upload split files or megapost with a lot of links