Gaining muscle whilst losing weight

A couple of things. First off, if you truly are 10% bodyfat, you do NOT have "ample reserves" to go on - you are skinny. If you want to stay and remain lean while building muscle, that is fine. The slang term online is "ottermode". Just be aware that you will build muscle more slowly than if you did a full bulk and then cut afterwards (something I would recommend).

First off, you need to build muscle. Since you don't want to do a full bulk, I suggest do a lean-bulk (eat at +250 calories over maintenance). This will keep fat gains minimal while building muscle. I know you want to cut and have abs, but you don't have any abs to show (at 10%, your abs should be clearly visible so if you can't see em, you don't got em). For 6 months, forget about the 6 pack - focus on building the ice chest to put the 6pack in. Once you built said muscle, cut and reveal it in all its glory.

Programming wise, yes you can do SL 5x5, though I suggest after 2 months of it, you switch to ICF 3x5 - it is basically the same thing with additional accessory work after the main lifts, which will help your aesthetics much more greatly than stronglifts or Starting strength.

Summary / Answering your questions:
1- you have no ample fat reserves, your progress on SL will stall very early, and you won't build muscle. go on a slow bulk of +250 calories over TDEE to gain muscle and minimal fat, then cut after done program (i.e. squat 1.5x bodyweight, bench 1xBW, deadlift 1.75xBW, OHP .75xBW.

2-You can build muscle on a cut as a noob. You can also build muscle doing Zamba dance class as a noob. you can do anything as a noob and get muscles, but none of it will take you very far. Noob Gains+bulk = your chance to build the most muscle in the shortest amount of time. Cut after.
Seriously. People go on steroids to match this level of rapid muscle gains because it doesn't last. Imagining being able to add +15lbs to your squat every week! The intermediate adds +5 to their max every week, and the advanced adds +5 to their max every month. Only the novice can boast such rapid strength gains.

3- You don't need to lose anymore IMO. If anything, putting on more muscle (at the same weight or even 10lbs heavier) will make you look better than you do - you can higher muscle mass and lower fat % at a higher weight. See my chart at the bottom - putting on more muscle at the same/a little more bodyfat will make you look much better.

Your goal is 'bodybuilding'. After you make good strength gains from SL / ICF, you can find an intermediate bodybuilding program afterwards to stay lean and muscular (i.e. PHAT or PHUL or PPLPPLx).

Edit:
Look at the various body types here. I am guessing your goals are between 2A to 4C. As long as your diet is on point, the above advice will get you there. Where are you at now?

nooneyuk88 wrote: »

1) Will my lifting progression suffer because I'm in a deficit, despite imo having ample fat reserves to go on.

Eventually yes, but in the short term (possibly even a few months) no.

nooneyuk88 wrote: »

2) Is it possible to put on muscle/ transfer fat to muscle whilst eating at a deficit or

3) Should I lose what I need to lose before starting a slow 200-300 deficit surplus to bulk.

It is possible, this is known as "Recomp", but it tends to be slow, slower than adding muscle and some fat and then dieting to lose that fat whilst retaining as much muscle as possible (known as the "bulking and then cutting").

Note: prob a typo but I corrected your quote above - you need surplus to bulk.

Best wishes

Not possible.

Short version: Lift, eat as many single ingredient foods in a deficit to cut or bulk to gain, be consistent, profit in a few months. Cheers