There are a lot of offerings from Voigtlander at the moment in the 35mm/40mm range: 40mm f1.2; the new 35mm f1.2, the 1.4s, and also the 35mm f2. I think it all comes down to what type of lens you would be looking for: something every day, reliable in most situations, or something with character and speed. If an every day lens, consider the 35mm f2.5 color skopar, 40mm rokkor m or 40mm summicron m. All can be had for a reasonable price. If you like something different, there is the 40mm f2.8 rollei sonnar which is ltm, so you can have a 35mm adapter which will bring up the 35mm framelines. If want something with character and speed, the noktons are worth a look. If heading to the 50mm, there are so many options...old and new. You can spend years exploring the various options and if sticking to Leica - vintage or new, Voigtlander, Zeiss, you can't go too wrong. Good luck! In my personal view with your camera I'd be looking to utilise the inbuilt framelines, so would go to either 35mm or 50mm, or 40mm ltm so you can bring up the 35mm framelines. 40mm using 50mm framelines takes a bit of guess work but you can get used to it pretty quickly - you will start seeing an imaginary floating frameline 🙂