[Radek]

You cannot get the boots by siding with Bodhi! You cannot get the boots by pickpocketing Renald!
When you accept Bodhi's offer, Renald Bloodscalp is removed from the game. The whole map of the Shadow Thieves HQ changes. No Renald - no boots. Aran Linvail does not have them.
It is possible to pickpocket Renhald Bloodscalp with enough high skill (above 200) but you get a few useless trinklets and nothing more. No boots.
The only way to the boots is killing Renald Bloodscalp while he is still present in the game, i.e., before you accept Bodhi's offer. AFAIK, you cannot kill Renald by a weapon, he has a "1 HP" item. The only way of getting him down is INT draining while you are shapeshifted to a mind flayer.

Therefore, the only "legitimate" way of getting the boots is the following:
1. Play a solo sorcerer or, perhaps, a party of two: sorcerer + someclass. Have the XP cap remover installed so that your sorcerer gets level 9 spells enough soon.
2. Feeblemind the whole "floor" with Renald in the thieves HQ.
3. Shapeshift to a mind flayer and kill Renald by INT draining.
Let us note that the "legitimate" way is pure nonsense. There are two pairs of the boots in the game so that a solo character or a party of two has no reason to do such things. A party of three will reach the necessary level for level 9 spells in the Underdark, i.e., too late.
Summary: even if it is possible to get the boots, getting the boots is either nonsense (solo character or a party of two) or it needs cheating. If you decide to cheat, you can cheat the boots directly - cheating the boots is the same as cheating anything else (level 9 scrolls, for example). You need not make your life difficult.