What would be the recommended tools I should try for de novo motif discovery in TSS regions (~1-2KB window around the TSS) of non-model vertebrate genomes?
As part of the standard pipeline, MEME-ChIP also runs DREME, which finds shorter motifs that standard MEME has a hard time with.
I've found MEME-ChIP very easy to use with nice HTML output, and the results I get are consistent with previous work.
It's probably still best to run another algorithm that uses a different strategy -- see this article in Nature Biotechnology for a great intro on the various strategies like enumeration, deterministic optimization, and probabilistic optimization.
Weeder (paper) might be a good choice for this; it was developed specifically for TSSs. However I'm not sure how well it handles big data so you might need to send it random subsamples of your data.
I do not have any experience with CisFinder.
The MEME suite (ref) is commonly used but it can break with 'big data' (sorry I have no quantification on this).
We have also had some success with Gimmemotifs for chip-seq data.
There are a large number of programs that find motifs with different methodologies. This paper compares a number of different programs. The paper is a bit old but most of the algorithms described in it have been updated with the times.
It has been over a year since I looked at MEME for ChIP-seq data. I will have another look at it thanks.