Solo Performance Issues

I have started to run into issues regarding my Solo Performances. The issue is that there aren't many backing tracks which are widely available for the two pieces that I'm playing. Vintage Trouble's 'Not Alright by Me' has no backing tracks online as they are quite a small band, however I'm friends with all of the members on Facebook and have asked them if they would be able to help with this. 'Sultans of Swing' is easier to find, but not for guitar and vocals - I thought it would be fun to sing on the track as it isn't too difficult and would sound better. There are currently no backing tracks for guitar and vocals, only for guitar OR vocals.

I have been practicing both pieces using the original tracks, so I could do that for the actual performance, however the guitar is one of the most dominant sounds on both tracks, and would not be easy to remove using Audacity. One idea that I've had is to download a guitar backing track with vocals on, and use Audacity to remove the vocals. This may work, but will not for 'Not Alright by Me'.

For the performance, I will probably have to play along to the original track. An alternative option is that I could play along to a live track and try to separate the guitar from the rest of the band. Whatever happens, I think that the performance will go well - I've been practicing 'Not Alright by Me' a lot since I started learning it, I've made a lot of progress with the piece and can now confidently play up to and including the solo - which is fantastic. The only issue I have is that I need to work on my finger strength. After the main riff, the piece progresses into a fingerpicked G, A, D sequence, the problem with this is that I have to use my thumb to pluck the three strings for the A Chord - however, my thumb isn't strong enough to make sufficient sound so I will have to work on that section, going over it numerous times until I can play it loud enough.

Sultans of Swing is also going well, however, I am still struggling a bit with remembering the chord timings. I know how to play the introduction (Dm, C, Bb, A, A7), however, the rhythm changes as the verses begin and I end up playing the chords too many times. This is an issue that I will have to counter by listening to the piece over and over, probably without vocals - just so I can hear exactly when the chord changes are. I'm also struggling with when the play the first fill, the rest of them are quite straight forward as they usually come after the full chord sequence, however the first is played after the Bb.

I will have to remember a lot for this piece, there are a lot of different fills, chord sequences and rhythm changes; but I am confident that I will be able to learn it in time, and perfect it for the performance in December.