For the GR1:
In 72nd, the Revell Tornado is by far the best.
In 48th, opinion varies as to whether the Airfix or Italeri kit is better.
The Airfix GR1 comes with all sorts of interesting stores - JP233, UK Paveway II; ALARM anti radar missiles plus 1000 pund iron bombs. It also has a TIALD pod, two 1500 litre 'Hindenburger' tanks and two of the smaller (1100 litre?? can't recall) tanks. the AIM-9s in the kit are a little 'weedy', though, and better replaced by some out of a Hasegawa weapons set.
The Italeri GR1 comes with just 4 x 1000 pound iron bombs, plus tanks and ECM pods.
To my eye, the Italeri kit captures the look of the Tornado better, but a good friend and colleague (and better modeller than I am) prefers the Airifx.
For the GR 4:
You only have the Airfix kit, which is a repop of their ancient GR1, with a sprue containing Paveway II, Alarm and Storm Shadow, plus the RAPTOR recce pod, TIALD pod, the correct underwing pods (i.e. not two Sky Shadow ECM pods) and the undernose FLIR housing.
Personally, I bought the Airifix kit with the intention of doing a nostalgic build of a GR1 (to remind me of the 10 I built between the ages of 8 and 12) from that and using the new parts for attachment to the Revell GR 1... It worked out as being cheaper than getting hold of the Airfix 72nd weapons set and the Airwaves FLIR housing (and that would still leave you without the Storm Shadow). Not an ideal solution for everyone, I guess, but it worked for me!
In 48th, the Airfix GR4 is the only game in town at the moment. This is the GR1 kit with 2 x Paveway IIIs, the FLIR housing & BOL Sidewinder pylons (these have the ability to dispense chaff in 'real life' and came in handy over Iraq for a couple of friends...).
Disappointingly, the array of weapons in the GR1 kit were not included in the GR4 kit - the only air-ground ordance you get is the two Paveways, plus the tanks and underwing pods.
I keep hearing reports that Airfix included the weapons sprues in the second run of kits. I have never seen this (in the UK), not do I have any idea of how you tell the difference between the kit that only has the Paveway III and those alleged to be complete with an interesting array of weapons.
For the Tornado F3:
1/72 - Revell/Italeri kit is supposed to be quite good (never built it myself so can't comment); Airfix kit is average; Hasegawa supposed to be the best of the bunch.
1/48th - Italeri somehow more satisfying, but a little hard to find.
Airfix kit recently re-released with lots of goodies - new upper fuselage part to improve on old F3 release; 4 x ASRAAM missiles and the inclusion of the two outer wing pylons that are fitted on operations to carry a towed radar decoy pod and a chaff/flare dispenser; you also, IIRC, get the BOL pylons as opposed to the old rails.
If Mr Hasegawa is reading this, though, he should be aware that a 1/48th Tornado GR4 and a 1/48th F3 would sell very nicely indeed in the UK!