Personally I fancy a Fretless but think i'd go with the Vintage Icon Fretless just like the look of them....if one comes up at the right price could be tempted.
Bought one a year or so ago can't complain at the price but took scratch plate off and as so often with cheap instruments hides a multitude of sins.....great big routing for the neck p/u.....put me off straight away....but for summat cheap and cheerful I suppose you could do worse.
Not sure but I dare say the paid content would be more in-depth, I have a couple of Marks courses Simple Steps to Walking Bass and Chord Tone Essentials but found they clash in content, but never the less they have some useful information in both.
The course you mention won't break the bank and i'm sure you will get plenty out of it, good luck.
Thought so Stew I am just dabbling with Theory as I haven't gigged in years and got to the point of either packing up or just going right back to basics...I always avoided theory in the past it looked so daunting but it's made a big difference and actually quite interesting, still just scratching the surface but knowing a bit can only benefit you in the long run all the best.
Don't know if this helps and forgive me if you already know but say for instance it's the Key of C Major the chords will be...
C Major
D Minor
E Minor
F Major
G Major
A Minor
B Diminished
The above will apply to any Major Key.
A good way of remembering the Cycle of Fourths is
C F (Bb Eb Ab Db Gb) (B E A D G)
Try to remember C F and the word BEAD G that's how I simplified it worked for me then play single notes in the cycle, then some simple triads it makes sense believe me, good luck