I mostly want to make a tale about MTFs working together to secure an SCP, possibly from a hostile GoI. Looking for possible SCPs to write about, ones that arn't exactly huge, something from series IV or V. I'm not sure if those are common or not, but I think it would be interesting.
This is just way too broad of an idea to be able to supply you with any insight. I think it could possibly work… but would need more information, like a plot, to really have any sort of opinion about it. All I know is that you're looking for skips that "aren't exactly huge".
Why don't you go through Series IV and V and pick out a few that you like? I would recommend messaging the authors to obtain their blessing, though…
I was planning initially on writing an SCP that would go with the tale, but that flopped, so I'm thinking about doing a potentially weaponized or weaponizable scp that is stored within a hostile groups possession. If anyone could also point me to some good combat tales I'll give them a good read.
You can still just make up an SCP for your tale, it doesn't have to have a pre-existing or successful file. That's what I did for Heart in the Hand of Matter. It also features an MTF in the field, but there's not really any combat in it. Sorry…
I think that, unless the anomaly / its effects are going to play a crucial role in the plot, then it's not necessarily so important which one you pick; or even that you pick one which already exists at all.
For example, I wrote Going In REDACTED about an MTF recontaining that particular SCP because the point of the story hinges on its anomalous effects. On the other hand, in Cat And Mouse this MTF's objective is to capture an anomalous person; but changing certain details of his character wouldn't greatly affect the overall plot.
So, unless you do have an idea of a particular SCP that is uniquely suited to the story you want to create, I'd say it's also acceptable to invent an 'as-yet-undocumented' SCP that can serve as the Macguffin of your tale.
Thanks to all of you, these will be a great help as I write.