I'm going to buy my first tube amp. I need honest blunt opinions

Looking at the Stereophile measurements you should take care in choosing a tube amp as the Gold 300s look like a bit of a harder load than one might initially expect.  Here’s an excerpt from John Atkinson’s measurements section…

Although Monitor Audio specifies the Gold 300's sensitivity as 90dB/W/m, my estimate was almost 3dB lower, at 87.3dB(B)/2.83V/m, perhaps due to the fact that the Gold 300's impedance is specified as 4 ohms. (An input of 2.83V is equivalent to 2W into 4 ohms.) The impedance magnitude (fig.1, solid trace) does stay close to 4 ohms from the upper bass through to the mid-treble, with minimum values of 3.7 ohms at 117Hz and 3.57 ohms at 1kHz. There is a current-hungry combination of 5 ohms and –39° electrical phase angle (dotted trace) at 77Hz, and the phase angle exceeds +40° above 10kHz, presumably due to the inductance of the MPD tweeter's drive system. The Monitor Audio needs to be partnered with an amplifier that is comfortable driving low impedances.

A “modest tube amp” might not get the job done here, so make sure to do your homework before fully committing.  In this case you might consider going with a tubed preamp rather than an amp to get some of that tube goodness.  Don’t mean to be a bummer here but thought I’d share this info in case you weren’t already aware.

I have had several different tube amps over the years.  40 and 50 watt EL34 and 6l6 amps.   They drove speakers around 90 dB sens in a room about 17 X 15    
 

My latest amp is a 40 watt Solid State amp and it can drive 86 dB sens speakers to pretty decent volumes cleanly in roughly the same size room. 
 

That said I would avoid low powered SET amps with those speakers and look at something 40 or 50 watts with tubes that are readily available is what I would suggest 

I have a 300b and it sounds beautiful but only with my Forte.  It just doesn’t have the power to play low to moderately low sensitivity speakers    

None of them do anything for me. 
Maybe have a look here:
Tube | New & Used Hi-Fi For Sale (audiogon.com)

Honestly? Quicksilver. See three options, today, here.

@marshinski15 , @soix has given you excellent advice. Four Ohm speakers are usually not the best way to be introduced to a tube amplifier. If it has an output transformer (and most do, but not all) you can lose as much as an octave of bandwidth in the bass department. Distortion will be higher too, and even though the output transformer might have a 4 Ohm tap, it will be less efficient so you'll have less power (although that will only be a few Watts at most). In addition your speaker cables become more critical.

If your speakers were 8 Ohms I would say any of the amps you listed would be fine.