For home use you could try finding online a Line 6 Guitar Pod 2.0 for the treble output. Second hand they are around £80 and easy to find in good condition.These little units have valve amp models,cabs and effects (tremelo chorous and fuzz should cover most Yes stuff) that are close enough to get you on the way to the Squire sound.(I have the original Bass Pod but if you need the effects above the guitar version has more effects and remember most valve amps are good for “Squire” bass whether it says “Bassman” “Showman” or “Superbass” or “Superlead” on the plate). Buy the Bass Pod if you cant find a good guitar Pod and you might need to add a tremelo pedal if you do. Tremelo is very key to parts of the CS sound and the Guitar Pod has tremelo onboard.
For the neck pickup try the Ampeg Analog Bass preamp. Its around £75 in most shops and will give you the rich bottom end to complete your sound. Its a great mono di pedal in its own right.
Now depending on how much volume you can get away with at home you could either buy a small mixer for £70 or so and mix both outputs plus your Yes track together and listen on headphones or buy a powered monitor such as an Alto TS210. These are about £260 or so. That way you can play along to your Youtube tv or Hi Fi without putting the bass through such small speakers.
If you have the powered speaker and no mixer you can simply plug each pickup into its own input and dial the level as you like it.
Thats about as basic as you could go expenditure wise I think.
The advantage of modelling is that you dont need a dedicated bass guitar amp to produce the sound. Believe me I have bought everything on the market over the years and still used my Line 6 Bass Pod for headphone practice.
Recently I bought the Line 6 Helix Rack for live use primarily because it has two independent channels and I now have a Fender Showman or Ampeg SVT4 at my disposal at the flick of a switch.
I hope my budget start up will save you enough cash to enable you to buy that 4003s. Check out the stuff Ive described and see what you think.